[vtk-developers] vtkProcessObject::GetNumberOfRequiredInputs()

[Andrew Dolgert]

Are you making a drag-and-drop visual interface more automatic than
Paraview?  Having more than just the number of inputs would let you
treat filters as components, with guarantees that, given the right
input, they will work.  Subclasses of vtkDataSet ensure the topology and
geometry are correct for a filter, but filters also have other
requirements on the dataset, such as whether there is scalar data and
whether it is on points or cells.  In the best of all possible worlds, I
would want to specify inputs and outputs in a declarative fashion.
Think of Prolog, with each class's rules specified in XML.  Then you
could verify the network as it is being built.
- Drew Dolgert, Cornell Theory Center

> Hi Everyone,
> 
> I'm wondering what people would think of adding a method
> GetNumberOfRequiredInputs() to vtkProcessObject.  It would
> make error checking e.g. in drag-and-drop style visual 
> pipeline building applications easier, since the app would 
> know ahead of time the minimum number of inputs a particular 
> filter requires.
> 
> Any thoughts?
> 
>  - David